Studies on Shirakawasuna-sand as a material for landscaping

Abstract

Shirakawasuna-sand has been used on the gardens in Kyoto since Heian era. Today Shirakawasuna-sand is used all over the country as a material for landscaping. Shirakawasuna-sand on the market is not river sand, but the crushed sand which is made of Kita-Shirakawa Granite at the plants at Kita-Shirakawa, Kyoto. The color of Shirakawasuna-sand is white. The shape of the grain of Shirakawasuna-sand is square. Shirakawasuna-sand is classified into 4 gradings.
The purpose of this paper is to clarify the qualities (physical properties) of Shirakawasunasand of today and the historical change of the qualities of Shirakawasuna-sand as a material for landscaping.
This study cleared the phisical properties of Shirakawasuna-sand by material tests. The physical properties of Shirakawasuna-sand is shown in Fig. 2 and Table 2. As compared with Shirakawasuna-sand on the market, the natural sand of the Shirakawa is too small in grain size.(Fig. 3) Grading characterizes the quality of Shirakawasuna-sand of today.
The historical change of the qualities of Shirakawasuna-sand was investigated by old literatures and pictures.
The study on Shirakawasuna-sand in early Edo era (17c.) is summarised as follows:
Shirakawasuna-sand was called Haku-sha (white sand). Haku-sha was the crushed sand made of Shirakawaishi-stone (Kita-Shirakawa Granite). It was produced as the result of the works of a greate many stone goods by the masons at Kita-Shirakawa. Haku-sha was classified by gradings to some extent.
It is inferred that the product of Haku-sha crushed sand traces back to late Muromachi era (16c.) at latest.
Shirakawasuna-sand is a half wrought material, and a special sand in various pebbles and sands for landscaping.